Non-destructive determining of foundation pile length variability for reliability analysis

Abstract

Contemporary design methods of foundation piles are more and more focused on sophisticated methods based on reliability analysis. Such methods, on different level of complicity, demand precise description of all data under study, not only by means of their average or characteristic values but, on higher levels of reliability analysis, standard deviations of basic variables, possible correlations and type of probability distribution. Most of the basic variables related to the ground were cautiously studied during last decades. The geometry of the pile itself (diameter and length) was usually assumed to be guaranteed and considered as non variable. The work tends to emphasize the role of pile length and present some examples of its non-destructive evaluation. Basic concepts of law strain integrity evaluation, elementary methods of reliability and sensibility analysis are presented and proceeded by results of excessive field testing programs. Some remarks on selection of basic random variables for pile capacity computation is given in discussion section. The results of the study confirm intuition that pile's length variability plays a secondary role in reliability assessment of pile's capacity.